Prevalence of hydroxychloroquine retinopathy with long-term use in a cohort of Indian patients with rheumatic diseases

Abstract

The study aims to estimate the prevalence of hydroxychloroquine (HCQ) retinopathy in a cohort of Indian patients and analyse the associated factors. Adult patients with rheumatological disorders aged ≥ 18years using HCQ for more than 5years and/or having received a cumulative dose > 400g were included. Demographic and clinical data were collected and all underwent ophthalmological tests which included Humphrey automated visual fields (AVF) and spectral domain optical coherence tomography (SD-OCT). The various clinical characteristics of the patients were compared. The study included 110 patients with a mean age of 43.5 ± 10.1years and predominantly females. Eleven patients (10%) were diagnosed with definite HCQ retinopathy. The mean daily dose of HCQ (mg/kg of real body weight) was significantly different in the groups with and without retinopathy (5.7 ± 0.9 vs 5.1 ± 0.8, p = 0.04). Patients with retinopathy had significantly more colour vision abnormalities (odds of 16.9; confidence interval 4.1-69.1, p = 0.0001) and higher prevalence of both parafoveal and perifoveal thinning (p < 0.0001). Age, gender, duration of HCQ use, cumulative HCQ dose and body mass index were not found to be associated with retinopathy. Four out of 11 patients had abnormalities only on 30-2 protocol for AVF testing, two had abnormalities only on 10-2 protocol, whereas five patients had abnormalities on both protocols. SD-OCT abnormalities were present in all patients with retinopathy. Hydroxychloroquine retinopathy was prevalent in the study cohort and significantly associated with a higher daily dose of HCQ (mg/kg real body weight).